Safe Haskell | None |
---|---|
Language | Haskell2010 |
Main functions for manipulating types and type-related things
Synopsis
- data TyThing
- data Type
- data ArgFlag
- type KindOrType = Type
- type PredType = Type
- type ThetaType = [PredType]
- data Var
- type TyVar = Var
- isTyVar :: Var -> Bool
- type TyCoVar = Id
- data TyBinder
- type TyVarBinder = TyVarBndr TyVar ArgFlag
- type KnotTied ty = ty
- mkTyVarTy :: TyVar -> Type
- mkTyVarTys :: [TyVar] -> [Type]
- getTyVar :: String -> Type -> TyVar
- getTyVar_maybe :: Type -> Maybe TyVar
- repGetTyVar_maybe :: Type -> Maybe TyVar
- getCastedTyVar_maybe :: Type -> Maybe (TyVar, CoercionN)
- tyVarKind :: TyVar -> Kind
- mkAppTy :: Type -> Type -> Type
- mkAppTys :: Type -> [Type] -> Type
- splitAppTy :: Type -> (Type, Type)
- splitAppTys :: Type -> (Type, [Type])
- repSplitAppTys :: HasDebugCallStack => Type -> (Type, [Type])
- splitAppTy_maybe :: Type -> Maybe (Type, Type)
- repSplitAppTy_maybe :: HasDebugCallStack => Type -> Maybe (Type, Type)
- tcRepSplitAppTy_maybe :: Type -> Maybe (Type, Type)
- mkFunTy :: Type -> Type -> Type
- mkFunTys :: [Type] -> Type -> Type
- splitFunTy :: Type -> (Type, Type)
- splitFunTy_maybe :: Type -> Maybe (Type, Type)
- splitFunTys :: Type -> ([Type], Type)
- funResultTy :: Type -> Type
- funArgTy :: Type -> Type
- mkTyConApp :: TyCon -> [Type] -> Type
- mkTyConTy :: TyCon -> Type
- tyConAppTyCon_maybe :: Type -> Maybe TyCon
- tyConAppTyConPicky_maybe :: Type -> Maybe TyCon
- tyConAppArgs_maybe :: Type -> Maybe [Type]
- tyConAppTyCon :: Type -> TyCon
- tyConAppArgs :: Type -> [Type]
- splitTyConApp_maybe :: HasDebugCallStack => Type -> Maybe (TyCon, [Type])
- splitTyConApp :: Type -> (TyCon, [Type])
- tyConAppArgN :: Int -> Type -> Type
- nextRole :: Type -> Role
- tcRepSplitTyConApp_maybe :: HasCallStack => Type -> Maybe (TyCon, [Type])
- tcSplitTyConApp_maybe :: HasCallStack => Type -> Maybe (TyCon, [Type])
- splitListTyConApp_maybe :: Type -> Maybe Type
- repSplitTyConApp_maybe :: HasDebugCallStack => Type -> Maybe (TyCon, [Type])
- mkForAllTy :: TyVar -> ArgFlag -> Type -> Type
- mkForAllTys :: [TyVarBinder] -> Type -> Type
- mkInvForAllTys :: [TyVar] -> Type -> Type
- mkSpecForAllTys :: [TyVar] -> Type -> Type
- mkVisForAllTys :: [TyVar] -> Type -> Type
- mkInvForAllTy :: TyVar -> Type -> Type
- splitForAllTys :: Type -> ([TyVar], Type)
- splitForAllTyVarBndrs :: Type -> ([TyVarBinder], Type)
- splitForAllTy_maybe :: Type -> Maybe (TyVar, Type)
- splitForAllTy :: Type -> (TyVar, Type)
- splitPiTy_maybe :: Type -> Maybe (TyBinder, Type)
- splitPiTy :: Type -> (TyBinder, Type)
- splitPiTys :: Type -> ([TyBinder], Type)
- mkPiTy :: TyBinder -> Type -> Type
- mkPiTys :: [TyBinder] -> Type -> Type
- mkTyConBindersPreferAnon :: [TyVar] -> Type -> [TyConBinder]
- mkLamType :: Var -> Type -> Type
- mkLamTypes :: [Var] -> Type -> Type
- piResultTy :: HasDebugCallStack => Type -> Type -> Type
- piResultTys :: HasDebugCallStack => Type -> [Type] -> Type
- applyTysX :: [TyVar] -> Type -> [Type] -> Type
- dropForAlls :: Type -> Type
- mkNumLitTy :: Integer -> Type
- isNumLitTy :: Type -> Maybe Integer
- mkStrLitTy :: FastString -> Type
- isStrLitTy :: Type -> Maybe FastString
- getRuntimeRep_maybe :: HasDebugCallStack => Type -> Maybe Type
- getRuntimeRepFromKind_maybe :: HasDebugCallStack => Type -> Maybe Type
- mkCastTy :: Type -> Coercion -> Type
- mkCoercionTy :: Coercion -> Type
- splitCastTy_maybe :: Type -> Maybe (Type, Coercion)
- userTypeError_maybe :: Type -> Maybe Type
- pprUserTypeErrorTy :: Type -> SDoc
- coAxNthLHS :: CoAxiom br -> Int -> Type
- stripCoercionTy :: Type -> Coercion
- splitCoercionType_maybe :: Type -> Maybe (Type, Type)
- splitPiTysInvisible :: Type -> ([TyBinder], Type)
- filterOutInvisibleTypes :: TyCon -> [Type] -> [Type]
- partitionInvisibles :: TyCon -> (a -> Type) -> [a] -> ([a], [a])
- synTyConResKind :: TyCon -> Kind
- modifyJoinResTy :: Int -> (Type -> Type) -> Type -> Type
- setJoinResTy :: Int -> Type -> Type -> Type
- data TyCoMapper env m = TyCoMapper {}
- mapType :: Monad m => TyCoMapper env m -> env -> Type -> m Type
- mapCoercion :: Monad m => TyCoMapper env m -> env -> Coercion -> m Coercion
- newTyConInstRhs :: TyCon -> [Type] -> Type
- mkFamilyTyConApp :: TyCon -> [Type] -> Type
- isDictLikeTy :: Type -> Bool
- mkPrimEqPred :: Type -> Type -> Type
- mkReprPrimEqPred :: Type -> Type -> Type
- mkPrimEqPredRole :: Role -> Type -> Type -> PredType
- equalityTyCon :: Role -> TyCon
- mkHeteroPrimEqPred :: Kind -> Kind -> Type -> Type -> Type
- mkHeteroReprPrimEqPred :: Kind -> Kind -> Type -> Type -> Type
- mkClassPred :: Class -> [Type] -> PredType
- isClassPred :: PredType -> Bool
- isEqPred :: PredType -> Bool
- isNomEqPred :: PredType -> Bool
- isIPPred :: PredType -> Bool
- isIPPred_maybe :: Type -> Maybe (FastString, Type)
- isIPTyCon :: TyCon -> Bool
- isIPClass :: Class -> Bool
- isCTupleClass :: Class -> Bool
- data PredTree
- data EqRel
- eqRelRole :: EqRel -> Role
- classifyPredType :: PredType -> PredTree
- getClassPredTys :: HasDebugCallStack => PredType -> (Class, [Type])
- getClassPredTys_maybe :: PredType -> Maybe (Class, [Type])
- getEqPredTys :: PredType -> (Type, Type)
- getEqPredTys_maybe :: PredType -> Maybe (Role, Type, Type)
- getEqPredRole :: PredType -> Role
- predTypeEqRel :: PredType -> EqRel
- sameVis :: ArgFlag -> ArgFlag -> Bool
- mkTyVarBinder :: ArgFlag -> Var -> TyVarBinder
- mkTyVarBinders :: ArgFlag -> [TyVar] -> [TyVarBinder]
- mkAnonBinder :: Type -> TyBinder
- isAnonTyBinder :: TyBinder -> Bool
- isNamedTyBinder :: TyBinder -> Bool
- binderVar :: TyVarBndr tv argf -> tv
- binderVars :: [TyVarBndr tv argf] -> [tv]
- binderKind :: TyVarBndr TyVar argf -> Kind
- binderArgFlag :: TyVarBndr tv argf -> argf
- tyBinderType :: TyBinder -> Type
- tyBinderVar_maybe :: TyBinder -> Maybe TyVar
- binderRelevantType_maybe :: TyBinder -> Maybe Type
- caseBinder :: TyBinder -> (TyVarBinder -> a) -> (Type -> a) -> a
- isVisibleArgFlag :: ArgFlag -> Bool
- isInvisibleArgFlag :: ArgFlag -> Bool
- isVisibleBinder :: TyBinder -> Bool
- isInvisibleBinder :: TyBinder -> Bool
- tyConBindersTyBinders :: [TyConBinder] -> [TyBinder]
- funTyCon :: TyCon
- isTyVarTy :: Type -> Bool
- isFunTy :: Type -> Bool
- isDictTy :: Type -> Bool
- isPredTy :: Type -> Bool
- isCoercionTy :: Type -> Bool
- isCoercionTy_maybe :: Type -> Maybe Coercion
- isCoercionType :: Type -> Bool
- isForAllTy :: Type -> Bool
- isPiTy :: Type -> Bool
- isTauTy :: Type -> Bool
- isFamFreeTy :: Type -> Bool
- isValidJoinPointType :: JoinArity -> Type -> Bool
- isLiftedType_maybe :: HasDebugCallStack => Type -> Maybe Bool
- isUnliftedType :: HasDebugCallStack => Type -> Bool
- isUnboxedTupleType :: Type -> Bool
- isUnboxedSumType :: Type -> Bool
- isAlgType :: Type -> Bool
- isDataFamilyAppType :: Type -> Bool
- isPrimitiveType :: Type -> Bool
- isStrictType :: HasDebugCallStack => Type -> Bool
- isRuntimeRepTy :: Type -> Bool
- isRuntimeRepVar :: TyVar -> Bool
- isRuntimeRepKindedTy :: Type -> Bool
- dropRuntimeRepArgs :: [Type] -> [Type]
- getRuntimeRep :: HasDebugCallStack => Type -> Type
- getRuntimeRepFromKind :: HasDebugCallStack => Type -> Type
- type Kind = Type
- typeKind :: HasDebugCallStack => Type -> Kind
- isTypeLevPoly :: Type -> Bool
- resultIsLevPoly :: Type -> Bool
- tcIsLiftedTypeKind :: Kind -> Bool
- tcIsConstraintKind :: Kind -> Bool
- tcReturnsConstraintKind :: Kind -> Bool
- liftedTypeKind :: Kind
- tyCoFVsOfType :: Type -> FV
- tyCoFVsBndr :: TyVarBinder -> FV -> FV
- tyCoVarsOfType :: Type -> TyCoVarSet
- tyCoVarsOfTypes :: [Type] -> TyCoVarSet
- tyCoVarsOfTypeDSet :: Type -> DTyCoVarSet
- coVarsOfType :: Type -> CoVarSet
- coVarsOfTypes :: [Type] -> TyCoVarSet
- closeOverKinds :: TyVarSet -> TyVarSet
- closeOverKindsList :: [TyVar] -> [TyVar]
- noFreeVarsOfType :: Type -> Bool
- splitVisVarsOfType :: Type -> Pair TyCoVarSet
- splitVisVarsOfTypes :: [Type] -> Pair TyCoVarSet
- expandTypeSynonyms :: Type -> Type
- typeSize :: Type -> Int
- occCheckExpand :: [Var] -> Type -> Maybe Type
- dVarSetElemsWellScoped :: DVarSet -> [Var]
- toposortTyVars :: [TyCoVar] -> [TyCoVar]
- tyCoVarsOfTypeWellScoped :: Type -> [TyVar]
- tyCoVarsOfTypesWellScoped :: [Type] -> [TyVar]
- eqType :: Type -> Type -> Bool
- eqTypeX :: RnEnv2 -> Type -> Type -> Bool
- eqTypes :: [Type] -> [Type] -> Bool
- nonDetCmpType :: Type -> Type -> Ordering
- nonDetCmpTypes :: [Type] -> [Type] -> Ordering
- nonDetCmpTypeX :: RnEnv2 -> Type -> Type -> Ordering
- nonDetCmpTypesX :: RnEnv2 -> [Type] -> [Type] -> Ordering
- nonDetCmpTc :: TyCon -> TyCon -> Ordering
- eqVarBndrs :: RnEnv2 -> [Var] -> [Var] -> Maybe RnEnv2
- seqType :: Type -> ()
- seqTypes :: [Type] -> ()
- coreView :: Type -> Maybe Type
- tcView :: Type -> Maybe Type
- tyConsOfType :: Type -> UniqSet TyCon
- type TvSubstEnv = TyVarEnv Type
- data TCvSubst = TCvSubst InScopeSet TvSubstEnv CvSubstEnv
- emptyTvSubstEnv :: TvSubstEnv
- emptyTCvSubst :: TCvSubst
- mkEmptyTCvSubst :: InScopeSet -> TCvSubst
- mkTCvSubst :: InScopeSet -> (TvSubstEnv, CvSubstEnv) -> TCvSubst
- zipTvSubst :: [TyVar] -> [Type] -> TCvSubst
- mkTvSubstPrs :: [(TyVar, Type)] -> TCvSubst
- notElemTCvSubst :: Var -> TCvSubst -> Bool
- getTvSubstEnv :: TCvSubst -> TvSubstEnv
- setTvSubstEnv :: TCvSubst -> TvSubstEnv -> TCvSubst
- zapTCvSubst :: TCvSubst -> TCvSubst
- getTCvInScope :: TCvSubst -> InScopeSet
- getTCvSubstRangeFVs :: TCvSubst -> VarSet
- extendTCvInScope :: TCvSubst -> Var -> TCvSubst
- extendTCvInScopeList :: TCvSubst -> [Var] -> TCvSubst
- extendTCvInScopeSet :: TCvSubst -> VarSet -> TCvSubst
- extendTCvSubst :: TCvSubst -> TyCoVar -> Type -> TCvSubst
- extendCvSubst :: TCvSubst -> CoVar -> Coercion -> TCvSubst
- extendTvSubst :: TCvSubst -> TyVar -> Type -> TCvSubst
- extendTvSubstBinderAndInScope :: TCvSubst -> TyBinder -> Type -> TCvSubst
- extendTvSubstList :: TCvSubst -> [Var] -> [Type] -> TCvSubst
- extendTvSubstAndInScope :: TCvSubst -> TyVar -> Type -> TCvSubst
- extendTvSubstWithClone :: TCvSubst -> TyVar -> TyVar -> TCvSubst
- isInScope :: Var -> TCvSubst -> Bool
- composeTCvSubstEnv :: InScopeSet -> (TvSubstEnv, CvSubstEnv) -> (TvSubstEnv, CvSubstEnv) -> (TvSubstEnv, CvSubstEnv)
- composeTCvSubst :: TCvSubst -> TCvSubst -> TCvSubst
- zipTyEnv :: [TyVar] -> [Type] -> TvSubstEnv
- zipCoEnv :: [CoVar] -> [Coercion] -> CvSubstEnv
- isEmptyTCvSubst :: TCvSubst -> Bool
- unionTCvSubst :: TCvSubst -> TCvSubst -> TCvSubst
- substTy :: HasCallStack => TCvSubst -> Type -> Type
- substTys :: HasCallStack => TCvSubst -> [Type] -> [Type]
- substTyWith :: HasCallStack => [TyVar] -> [Type] -> Type -> Type
- substTysWith :: [TyVar] -> [Type] -> [Type] -> [Type]
- substTheta :: HasCallStack => TCvSubst -> ThetaType -> ThetaType
- substTyAddInScope :: TCvSubst -> Type -> Type
- substTyUnchecked :: TCvSubst -> Type -> Type
- substTysUnchecked :: TCvSubst -> [Type] -> [Type]
- substThetaUnchecked :: TCvSubst -> ThetaType -> ThetaType
- substTyWithUnchecked :: [TyVar] -> [Type] -> Type -> Type
- substCoUnchecked :: TCvSubst -> Coercion -> Coercion
- substCoWithUnchecked :: [TyVar] -> [Type] -> Coercion -> Coercion
- substTyVarBndr :: HasCallStack => TCvSubst -> TyVar -> (TCvSubst, TyVar)
- substTyVarBndrs :: HasCallStack => TCvSubst -> [TyVar] -> (TCvSubst, [TyVar])
- substTyVar :: TCvSubst -> TyVar -> Type
- substTyVars :: TCvSubst -> [TyVar] -> [Type]
- cloneTyVarBndr :: TCvSubst -> TyVar -> Unique -> (TCvSubst, TyVar)
- cloneTyVarBndrs :: TCvSubst -> [TyVar] -> UniqSupply -> (TCvSubst, [TyVar])
- lookupTyVar :: TCvSubst -> TyVar -> Maybe Type
- pprType :: Type -> SDoc
- pprParendType :: Type -> SDoc
- pprPrecType :: PprPrec -> Type -> SDoc
- pprTypeApp :: TyCon -> [Type] -> SDoc
- pprTyThingCategory :: TyThing -> SDoc
- pprShortTyThing :: TyThing -> SDoc
- pprTvBndr :: TyVarBinder -> SDoc
- pprTvBndrs :: [TyVarBinder] -> SDoc
- pprForAll :: [TyVarBinder] -> SDoc
- pprUserForAll :: [TyVarBinder] -> SDoc
- pprSigmaType :: Type -> SDoc
- ppSuggestExplicitKinds :: SDoc
- pprTheta :: ThetaType -> SDoc
- pprThetaArrowTy :: ThetaType -> SDoc
- pprClassPred :: Class -> [Type] -> SDoc
- pprKind :: Kind -> SDoc
- pprParendKind :: Kind -> SDoc
- pprSourceTyCon :: TyCon -> SDoc
- newtype PprPrec = PprPrec Int
- topPrec :: PprPrec
- sigPrec :: PprPrec
- opPrec :: PprPrec
- funPrec :: PprPrec
- appPrec :: PprPrec
- maybeParen :: PprPrec -> PprPrec -> SDoc -> SDoc
- pprTyVar :: TyVar -> SDoc
- pprTyVars :: [TyVar] -> SDoc
- pprWithTYPE :: Type -> SDoc
- tidyType :: TidyEnv -> Type -> Type
- tidyTypes :: TidyEnv -> [Type] -> [Type]
- tidyOpenType :: TidyEnv -> Type -> (TidyEnv, Type)
- tidyOpenTypes :: TidyEnv -> [Type] -> (TidyEnv, [Type])
- tidyOpenKind :: TidyEnv -> Kind -> (TidyEnv, Kind)
- tidyTyCoVarBndr :: TidyEnv -> TyCoVar -> (TidyEnv, TyCoVar)
- tidyTyCoVarBndrs :: TidyEnv -> [TyCoVar] -> (TidyEnv, [TyCoVar])
- tidyFreeTyCoVars :: TidyEnv -> [TyCoVar] -> TidyEnv
- tidyOpenTyCoVar :: TidyEnv -> TyCoVar -> (TidyEnv, TyCoVar)
- tidyOpenTyCoVars :: TidyEnv -> [TyCoVar] -> (TidyEnv, [TyCoVar])
- tidyTyVarOcc :: TidyEnv -> TyVar -> TyVar
- tidyTopType :: Type -> Type
- tidyKind :: TidyEnv -> Kind -> Kind
- tidyTyVarBinder :: TidyEnv -> TyVarBndr TyVar vis -> (TidyEnv, TyVarBndr TyVar vis)
- tidyTyVarBinders :: TidyEnv -> [TyVarBndr TyVar vis] -> (TidyEnv, [TyVarBndr TyVar vis])
Main data types representing Types
Types are one of:
- Unboxed
- Iff its representation is other than a pointer Unboxed types are also unlifted.
- Lifted
- Iff it has bottom as an element. Closures always have lifted types: i.e. any let-bound identifier in Core must have a lifted type. Operationally, a lifted object is one that can be entered. Only lifted types may be unified with a type variable.
- Algebraic
- Iff it is a type with one or more constructors, whether
declared with
data
ornewtype
. An algebraic type is one that can be deconstructed with a case expression. This is not the same as lifted types, because we also include unboxed tuples in this classification. - Data
- Iff it is a type declared with
data
, or a boxed tuple. - Primitive
- Iff it is a built-in type that can't be expressed in Haskell.
Currently, all primitive types are unlifted, but that's not necessarily
the case: for example, Int
could be primitive.
Some primitive types are unboxed, such as Int#
, whereas some are boxed
but unlifted (such as ByteArray#
). The only primitive types that we
classify as algebraic are the unboxed tuples.
Some examples of type classifications that may make this a bit clearer are:
Type primitive boxed lifted algebraic ----------------------------------------------------------------------------- Int# Yes No No No ByteArray# Yes Yes No No (# a, b #) Yes No No Yes (# a | b #) Yes No No Yes ( a, b ) No Yes Yes Yes [a] No Yes Yes Yes
A source type is a type that is a separate type as far as the type checker is concerned, but which has a more low-level representation as far as Core-to-Core passes and the rest of the back end is concerned.
You don't normally have to worry about this, as the utility functions in this module will automatically convert a source into a representation type if they are spotted, to the best of it's abilities. If you don't want this to happen, use the equivalent functions from the TcType module.
Instances
Data Type # | |
Defined in TyCoRep gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Type -> c Type Source # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Type Source # toConstr :: Type -> Constr Source # dataTypeOf :: Type -> DataType Source # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Type) Source # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Type) Source # gmapT :: (forall b. Data b => b -> b) -> Type -> Type Source # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Type -> r Source # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Type -> r Source # gmapQ :: (forall d. Data d => d -> u) -> Type -> [u] Source # gmapQi :: Int -> (forall d. Data d => d -> u) -> Type -> u Source # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Type -> m Type Source # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Type -> m Type Source # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Type -> m Type Source # | |
Outputable Type # | |
Argument Flag
Is something required to appear in source Haskell (Required
),
permitted by request (Specified
) (visible type application), or
prohibited entirely from appearing in source Haskell (Inferred
)?
See Note [TyVarBndrs, TyVarBinders, TyConBinders, and visibility] in TyCoRep
Instances
Eq ArgFlag # | |
Data ArgFlag # | |
Defined in Var gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ArgFlag -> c ArgFlag Source # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ArgFlag Source # toConstr :: ArgFlag -> Constr Source # dataTypeOf :: ArgFlag -> DataType Source # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c ArgFlag) Source # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ArgFlag) Source # gmapT :: (forall b. Data b => b -> b) -> ArgFlag -> ArgFlag Source # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ArgFlag -> r Source # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ArgFlag -> r Source # gmapQ :: (forall d. Data d => d -> u) -> ArgFlag -> [u] Source # gmapQi :: Int -> (forall d. Data d => d -> u) -> ArgFlag -> u Source # gmapM :: Monad m => (forall d. Data d => d -> m d) -> ArgFlag -> m ArgFlag Source # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ArgFlag -> m ArgFlag Source # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ArgFlag -> m ArgFlag Source # | |
Ord ArgFlag # | |
Outputable ArgFlag # | |
Binary ArgFlag # | |
Outputable tv => Outputable (TyVarBndr tv ArgFlag) # | |
type KindOrType = Type Source #
The key representation of types within the compiler
A type of the form p
of kind Constraint
represents a value whose type is
the Haskell predicate p
, where a predicate is what occurs before
the =>
in a Haskell type.
We use PredType
as documentation to mark those types that we guarantee to have
this kind.
It can be expanded into its representation, but:
- The type checker must treat it as opaque
- The rest of the compiler treats it as transparent
Consider these examples:
f :: (Eq a) => a -> Int g :: (?x :: Int -> Int) => a -> Int h :: (r\l) => {r} => {l::Int | r}
Here the Eq a
and ?x :: Int -> Int
and rl
are all called "predicates"
Variable
Essentially a typed Name
, that may also contain some additional information
about the Var
and it's use sites.
Instances
Eq Var # | |
Data Var # | |
Defined in Var gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Var -> c Var Source # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Var Source # toConstr :: Var -> Constr Source # dataTypeOf :: Var -> DataType Source # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Var) Source # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Var) Source # gmapT :: (forall b. Data b => b -> b) -> Var -> Var Source # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Var -> r Source # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Var -> r Source # gmapQ :: (forall d. Data d => d -> u) -> Var -> [u] Source # gmapQi :: Int -> (forall d. Data d => d -> u) -> Var -> u Source # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Var -> m Var Source # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Var -> m Var Source # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Var -> m Var Source # | |
Ord Var # | |
OutputableBndr Var # | |
Outputable Var # | |
Uniquable Var # | |
HasOccName Var # | |
NamedThing Var # | |
A TyBinder
represents an argument to a function. TyBinders can be dependent
(Named
) or nondependent (Anon
). They may also be visible or not.
See Note [TyBinders]
Instances
Data TyBinder # | |
Defined in TyCoRep gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> TyBinder -> c TyBinder Source # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c TyBinder Source # toConstr :: TyBinder -> Constr Source # dataTypeOf :: TyBinder -> DataType Source # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c TyBinder) Source # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c TyBinder) Source # gmapT :: (forall b. Data b => b -> b) -> TyBinder -> TyBinder Source # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> TyBinder -> r Source # gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> TyBinder -> r Source # gmapQ :: (forall d. Data d => d -> u) -> TyBinder -> [u] Source # gmapQi :: Int -> (forall d. Data d => d -> u) -> TyBinder -> u Source # gmapM :: Monad m => (forall d. Data d => d -> m d) -> TyBinder -> m TyBinder Source # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> TyBinder -> m TyBinder Source # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> TyBinder -> m TyBinder Source # | |
Outputable TyBinder # | |
type TyVarBinder = TyVarBndr TyVar ArgFlag Source #
Type Variable Binder
A TyVarBinder
is the binder of a ForAllTy
It's convenient to define this synonym here rather its natural
home in TyCoRep, because it's used in DataCon.hs-boot
type KnotTied ty = ty Source #
A type labeled KnotTied
might have knot-tied tycons in it. See
Note [Type checking recursive type and class declarations] in
TcTyClsDecls
Constructing and deconstructing types
mkTyVarTys :: [TyVar] -> [Type] Source #
getTyVar :: String -> Type -> TyVar Source #
Attempts to obtain the type variable underlying a Type
, and panics with the
given message if this is not a type variable type. See also getTyVar_maybe
getTyVar_maybe :: Type -> Maybe TyVar Source #
Attempts to obtain the type variable underlying a Type
repGetTyVar_maybe :: Type -> Maybe TyVar Source #
Attempts to obtain the type variable underlying a Type
, without
any expansion
getCastedTyVar_maybe :: Type -> Maybe (TyVar, CoercionN) Source #
If the type is a tyvar, possibly under a cast, returns it, along with the coercion. Thus, the co is :: kind tv ~N kind type
splitAppTy :: Type -> (Type, Type) Source #
Attempts to take a type application apart, as in splitAppTy_maybe
,
and panics if this is not possible
splitAppTys :: Type -> (Type, [Type]) Source #
Recursively splits a type as far as is possible, leaving a residual type being applied to and the type arguments applied to it. Never fails, even if that means returning an empty list of type applications.
repSplitAppTys :: HasDebugCallStack => Type -> (Type, [Type]) Source #
Like splitAppTys
, but doesn't look through type synonyms
splitAppTy_maybe :: Type -> Maybe (Type, Type) Source #
Attempt to take a type application apart, whether it is a function, type constructor, or plain type application. Note that type family applications are NEVER unsaturated by this!
repSplitAppTy_maybe :: HasDebugCallStack => Type -> Maybe (Type, Type) Source #
Does the AppTy split as in splitAppTy_maybe
, but assumes that
any Core view stuff is already done
tcRepSplitAppTy_maybe :: Type -> Maybe (Type, Type) Source #
Does the AppTy split as in tcSplitAppTy_maybe
, but assumes that
any coreView stuff is already done. Refuses to look through (c => t)
splitFunTy :: Type -> (Type, Type) Source #
Attempts to extract the argument and result types from a type, and
panics if that is not possible. See also splitFunTy_maybe
splitFunTy_maybe :: Type -> Maybe (Type, Type) Source #
Attempts to extract the argument and result types from a type
funResultTy :: Type -> Type Source #
Extract the function result type and panic if that is not possible
funArgTy :: Type -> Type Source #
Extract the function argument type and panic if that is not possible
mkTyConApp :: TyCon -> [Type] -> Type Source #
A key function: builds a TyConApp
or FunTy
as appropriate to
its arguments. Applies its arguments to the constructor from left to right.
mkTyConTy :: TyCon -> Type Source #
Create the plain type constructor type which has been applied to no type arguments at all.
tyConAppTyConPicky_maybe :: Type -> Maybe TyCon Source #
Retrieve the tycon heading this type, if there is one. Does not look through synonyms.
tyConAppTyCon :: Type -> TyCon Source #
tyConAppArgs :: Type -> [Type] Source #
splitTyConApp_maybe :: HasDebugCallStack => Type -> Maybe (TyCon, [Type]) Source #
Attempts to tease a type apart into a type constructor and the application of a number of arguments to that constructor
splitTyConApp :: Type -> (TyCon, [Type]) Source #
Attempts to tease a type apart into a type constructor and the application
of a number of arguments to that constructor. Panics if that is not possible.
See also splitTyConApp_maybe
tcRepSplitTyConApp_maybe :: HasCallStack => Type -> Maybe (TyCon, [Type]) Source #
Like tcSplitTyConApp_maybe
but doesn't look through type synonyms.
tcSplitTyConApp_maybe :: HasCallStack => Type -> Maybe (TyCon, [Type]) Source #
Split a type constructor application into its type constructor and
applied types. Note that this may fail in the case of a FunTy
with an
argument of unknown kind FunTy
(e.g. FunTy (a :: k) Int
. since the kind
of a
isn't of the form TYPE rep
). Consequently, you may need to zonk your
type before using this function.
If you only need the TyCon
, consider using tcTyConAppTyCon_maybe
.
splitListTyConApp_maybe :: Type -> Maybe Type Source #
Attempts to tease a list type apart and gives the type of the elements if successful (looks through type synonyms)
repSplitTyConApp_maybe :: HasDebugCallStack => Type -> Maybe (TyCon, [Type]) Source #
Like splitTyConApp_maybe
, but doesn't look through synonyms. This
assumes the synonyms have already been dealt with.
mkForAllTys :: [TyVarBinder] -> Type -> Type Source #
Wraps foralls over the type using the provided TyVar
s from left to right
mkInvForAllTys :: [TyVar] -> Type -> Type Source #
Like mkForAllTys, but assumes all variables are dependent and Inferred, a common case
mkSpecForAllTys :: [TyVar] -> Type -> Type Source #
Like mkForAllTys, but assumes all variables are dependent and specified, a common case
mkVisForAllTys :: [TyVar] -> Type -> Type Source #
Like mkForAllTys, but assumes all variables are dependent and visible
mkInvForAllTy :: TyVar -> Type -> Type Source #
Make a dependent forall over an Inferred (as opposed to Specified) variable
splitForAllTys :: Type -> ([TyVar], Type) Source #
Take a ForAllTy apart, returning the list of tyvars and the result type. This always succeeds, even if it returns only an empty list. Note that the result type returned may have free variables that were bound by a forall.
splitForAllTyVarBndrs :: Type -> ([TyVarBinder], Type) Source #
Like splitPiTys
but split off only named binders.
splitForAllTy_maybe :: Type -> Maybe (TyVar, Type) Source #
Attempts to take a forall type apart, but only if it's a proper forall, with a named binder
splitForAllTy :: Type -> (TyVar, Type) Source #
Take a forall type apart, or panics if that is not possible.
splitPiTy_maybe :: Type -> Maybe (TyBinder, Type) Source #
Attempts to take a forall type apart; works with proper foralls and functions
splitPiTys :: Type -> ([TyBinder], Type) Source #
Split off all TyBinders to a type, splitting both proper foralls and functions
mkTyConBindersPreferAnon :: [TyVar] -> Type -> [TyConBinder] Source #
Given a list of type-level vars and a result kind, makes TyBinders, preferring anonymous binders if the variable is, in fact, not dependent. e.g. mkTyConBindersPreferAnon (k:*),(b:k),(c:k) We want (k:*) Named, (a;k) Anon, (c:k) Anon
All binders are visible.
mkLamType :: Var -> Type -> Type Source #
Makes a (->)
type or an implicit forall type, depending
on whether it is given a type variable or a term variable.
This is used, for example, when producing the type of a lambda.
Always uses Inferred binders.
piResultTy :: HasDebugCallStack => Type -> Type -> Type Source #
piResultTys :: HasDebugCallStack => Type -> [Type] -> Type Source #
(piResultTys f_ty [ty1, .., tyn]) gives the type of (f ty1 .. tyn)
where f :: f_ty
piResultTys
is interesting because:
1. f_ty
may have more for-alls than there are args
2. Less obviously, it may have fewer for-alls
For case 2. think of:
piResultTys (forall a.a) [forall b.b, Int]
This really can happen, but only (I think) in situations involving
undefined. For example:
undefined :: forall a. a
Term: undefined (forall b. b->b)
Int
This term should have type (Int -> Int), but notice that
there are more type args than foralls in undefined
s type.
dropForAlls :: Type -> Type Source #
Drops all ForAllTys
mkNumLitTy :: Integer -> Type Source #
isNumLitTy :: Type -> Maybe Integer Source #
Is this a numeric literal. We also look through type synonyms.
mkStrLitTy :: FastString -> Type Source #
isStrLitTy :: Type -> Maybe FastString Source #
Is this a symbol literal. We also look through type synonyms.
getRuntimeRep_maybe :: HasDebugCallStack => Type -> Maybe Type Source #
Extract the RuntimeRep classifier of a type. For instance,
getRuntimeRep_maybe Int = LiftedRep
. Returns Nothing
if this is not
possible.
getRuntimeRepFromKind_maybe :: HasDebugCallStack => Type -> Maybe Type Source #
Extract the RuntimeRep classifier of a type from its kind. For example,
getRuntimeRepFromKind * = LiftedRep
; Returns Nothing
if this is not
possible.
mkCastTy :: Type -> Coercion -> Type Source #
Make a CastTy
. The Coercion must be nominal. Checks the
Coercion for reflexivity, dropping it if it's reflexive.
See Note [Respecting definitional equality] in TyCoRep
mkCoercionTy :: Coercion -> Type Source #
userTypeError_maybe :: Type -> Maybe Type Source #
Is this type a custom user error? If so, give us the kind and the error message.
pprUserTypeErrorTy :: Type -> SDoc Source #
Render a type corresponding to a user type error into a SDoc.
coAxNthLHS :: CoAxiom br -> Int -> Type Source #
Get the type on the LHS of a coercion induced by a type/data family instance.
stripCoercionTy :: Type -> Coercion Source #
splitCoercionType_maybe :: Type -> Maybe (Type, Type) Source #
Try to split up a coercion type into the types that it coerces
filterOutInvisibleTypes :: TyCon -> [Type] -> [Type] Source #
Given a tycon and its arguments, filters out any invisible arguments
partitionInvisibles :: TyCon -> (a -> Type) -> [a] -> ([a], [a]) Source #
Given a tycon and a list of things (which correspond to arguments), partitions the things into Inferred or Specified ones and Required ones The callback function is necessary for this scenario:
T :: forall k. k -> k partitionInvisibles T [forall m. m -> m -> m, S, R, Q]
After substituting, we get
T (forall m. m -> m -> m) :: (forall m. m -> m -> m) -> forall n. n -> n -> n
Thus, the first argument is invisible, S
is visible, R
is invisible again,
and Q
is visible.
If you're absolutely sure that your tycon's kind doesn't end in a variable, it's OK if the callback function panics, as that's the only time it's consulted.
synTyConResKind :: TyCon -> Kind Source #
data TyCoMapper env m Source #
This describes how a "map" operation over a type/coercion should behave
TyCoMapper | |
|
mapCoercion :: Monad m => TyCoMapper env m -> env -> Coercion -> m Coercion Source #
newTyConInstRhs :: TyCon -> [Type] -> Type Source #
Unwrap one layer
of newtype on a type constructor and its
arguments, using an eta-reduced version of the newtype
if possible.
This requires tys to have at least newTyConInstArity tycon
elements.
mkFamilyTyConApp :: TyCon -> [Type] -> Type Source #
Given a family instance TyCon and its arg types, return the corresponding family type. E.g:
data family T a data instance T (Maybe b) = MkT b
Where the instance tycon is :RTL, so:
mkFamilyTyConApp :RTL Int = T (Maybe Int)
isDictLikeTy :: Type -> Bool Source #
mkPrimEqPred :: Type -> Type -> Type Source #
Creates a primitive type equality predicate. Invariant: the types are not Coercions
mkPrimEqPredRole :: Role -> Type -> Type -> PredType Source #
Makes a lifted equality predicate at the given role
equalityTyCon :: Role -> TyCon Source #
mkHeteroPrimEqPred :: Kind -> Kind -> Type -> Type -> Type Source #
Creates a primite type equality predicate with explicit kinds
mkHeteroReprPrimEqPred :: Kind -> Kind -> Type -> Type -> Type Source #
Creates a primitive representational type equality predicate with explicit kinds
isClassPred :: PredType -> Bool Source #
isNomEqPred :: PredType -> Bool Source #
isIPPred_maybe :: Type -> Maybe (FastString, Type) Source #
isCTupleClass :: Class -> Bool Source #
A choice of equality relation. This is separate from the type Role
because Phantom
does not define a (non-trivial) equality relation.
classifyPredType :: PredType -> PredTree Source #
getClassPredTys :: HasDebugCallStack => PredType -> (Class, [Type]) Source #
getEqPredRole :: PredType -> Role Source #
predTypeEqRel :: PredType -> EqRel Source #
Get the equality relation relevant for a pred type.
Binders
mkTyVarBinder :: ArgFlag -> Var -> TyVarBinder Source #
Make a named binder
mkTyVarBinders :: ArgFlag -> [TyVar] -> [TyVarBinder] Source #
Make many named binders
mkAnonBinder :: Type -> TyBinder Source #
Make an anonymous binder
isAnonTyBinder :: TyBinder -> Bool Source #
Does this binder bind a variable that is not erased? Returns
True
for anonymous binders.
isNamedTyBinder :: TyBinder -> Bool Source #
binderVars :: [TyVarBndr tv argf] -> [tv] Source #
binderArgFlag :: TyVarBndr tv argf -> argf Source #
tyBinderType :: TyBinder -> Type Source #
binderRelevantType_maybe :: TyBinder -> Maybe Type Source #
Extract a relevant type, if there is one.
:: TyBinder | binder to scrutinize |
-> (TyVarBinder -> a) | named case |
-> (Type -> a) | anonymous case |
-> a |
Like maybe
, but for binders.
isVisibleArgFlag :: ArgFlag -> Bool Source #
Does this ArgFlag
classify an argument that is written in Haskell?
isInvisibleArgFlag :: ArgFlag -> Bool Source #
Does this ArgFlag
classify an argument that is not written in Haskell?
isVisibleBinder :: TyBinder -> Bool Source #
Does this binder bind a visible argument?
isInvisibleBinder :: TyBinder -> Bool Source #
Does this binder bind an invisible argument?
tyConBindersTyBinders :: [TyConBinder] -> [TyBinder] Source #
Common type constructors
The (->)
type constructor.
(->) :: forall (rep1 :: RuntimeRep) (rep2 :: RuntimeRep). TYPE rep1 -> TYPE rep2 -> *
Predicates on types
isPredTy :: Type -> Bool Source #
Is the type suitable to classify a given/wanted in the typechecker?
isCoercionTy :: Type -> Bool Source #
isCoercionType :: Type -> Bool Source #
isForAllTy :: Type -> Bool Source #
Checks whether this is a proper forall (with a named binder)
isFamFreeTy :: Type -> Bool Source #
isValidJoinPointType :: JoinArity -> Type -> Bool Source #
Determine whether a type could be the type of a join point of given total
arity, according to the polymorphism rule. A join point cannot be polymorphic
in its return type, since given
join j a
b x y z = e1 in e2,
the types of e1 and e2 must be the same, and a and b are not in scope for e2.
(See Note [The polymorphism rule of join points] in CoreSyn.) Returns False
also if the type simply doesn't have enough arguments.
Note that we need to know how many arguments (type *and* value) the putative join point takes; for instance, if j :: forall a. a -> Int then j could be a binary join point returning an Int, but it could *not* be a unary join point returning a -> Int.
TODO: See Note [Excess polymorphism and join points]
isLiftedType_maybe :: HasDebugCallStack => Type -> Maybe Bool Source #
Returns Just True if this type is surely lifted, Just False if it is surely unlifted, Nothing if we can't be sure (i.e., it is levity polymorphic), and panics if the kind does not have the shape TYPE r.
isUnliftedType :: HasDebugCallStack => Type -> Bool Source #
See Type for what an unlifted type is. Panics on levity polymorphic types.
isUnboxedTupleType :: Type -> Bool Source #
isUnboxedSumType :: Type -> Bool Source #
isAlgType :: Type -> Bool Source #
See Type for what an algebraic type is. Should only be applied to types, as opposed to e.g. partially saturated type constructors
isDataFamilyAppType :: Type -> Bool Source #
Check whether a type is a data family type
isPrimitiveType :: Type -> Bool Source #
Returns true of types that are opaque to Haskell.
isStrictType :: HasDebugCallStack => Type -> Bool Source #
Computes whether an argument (or let right hand side) should
be computed strictly or lazily, based only on its type.
Currently, it's just isUnliftedType
. Panics on levity-polymorphic types.
isRuntimeRepTy :: Type -> Bool Source #
Is this the type RuntimeRep
?
isRuntimeRepVar :: TyVar -> Bool Source #
Is a tyvar of type RuntimeRep
?
isRuntimeRepKindedTy :: Type -> Bool Source #
Is this a type of kind RuntimeRep? (e.g. LiftedRep)
dropRuntimeRepArgs :: [Type] -> [Type] Source #
getRuntimeRep :: HasDebugCallStack => Type -> Type Source #
Extract the RuntimeRep classifier of a type. For instance,
getRuntimeRep_maybe Int = LiftedRep
. Panics if this is not possible.
getRuntimeRepFromKind :: HasDebugCallStack => Type -> Type Source #
Extract the RuntimeRep classifier of a type from its kind. For example,
getRuntimeRepFromKind * = LiftedRep
; Panics if this is not possible.
Main data types representing Kinds
Finding the kind of a type
isTypeLevPoly :: Type -> Bool Source #
Returns True if a type is levity polymorphic. Should be the same as (isKindLevPoly . typeKind) but much faster. Precondition: The type has kind (TYPE blah)
resultIsLevPoly :: Type -> Bool Source #
Looking past all pi-types, is the end result potentially levity polymorphic? Example: True for (forall r (a :: TYPE r). String -> a) Example: False for (forall r1 r2 (a :: TYPE r1) (b :: TYPE r2). a -> b -> Type)
tcIsLiftedTypeKind :: Kind -> Bool Source #
Is this kind equivalent to *
?
This considers Constraint
to be distinct from *
. For a version that
treats them as the same type, see isLiftedTypeKind
.
tcIsConstraintKind :: Kind -> Bool Source #
tcReturnsConstraintKind :: Kind -> Bool Source #
Common Kind
Type free variables
tyCoFVsOfType :: Type -> FV Source #
The worker for tyCoFVsOfType
and tyCoFVsOfTypeList
.
The previous implementation used unionVarSet
which is O(n+m) and can
make the function quadratic.
It's exported, so that it can be composed with
other functions that compute free variables.
See Note [FV naming conventions] in FV.
Eta-expanded because that makes it run faster (apparently) See Note [FV eta expansion] in FV for explanation.
tyCoFVsBndr :: TyVarBinder -> FV -> FV Source #
tyCoVarsOfType :: Type -> TyCoVarSet Source #
Returns free variables of a type, including kind variables as a non-deterministic set. For type synonyms it does not expand the synonym.
tyCoVarsOfTypes :: [Type] -> TyCoVarSet Source #
Returns free variables of types, including kind variables as a non-deterministic set. For type synonyms it does not expand the synonym.
tyCoVarsOfTypeDSet :: Type -> DTyCoVarSet Source #
tyCoFVsOfType
that returns free variables of a type in a deterministic
set. For explanation of why using VarSet
is not deterministic see
Note [Deterministic FV] in FV.
coVarsOfType :: Type -> CoVarSet Source #
coVarsOfTypes :: [Type] -> TyCoVarSet Source #
closeOverKinds :: TyVarSet -> TyVarSet Source #
Add the kind variables free in the kinds of the tyvars in the given set. Returns a non-deterministic set.
closeOverKindsList :: [TyVar] -> [TyVar] Source #
Add the kind variables free in the kinds of the tyvars in the given set. Returns a deterministically ordered list.
noFreeVarsOfType :: Type -> Bool Source #
Returns True if this type has no free variables. Should be the same as isEmptyVarSet . tyCoVarsOfType, but faster in the non-forall case.
splitVisVarsOfType :: Type -> Pair TyCoVarSet Source #
Retrieve the free variables in this type, splitting them based on whether they are used visibly or invisibly. Invisible ones come first.
splitVisVarsOfTypes :: [Type] -> Pair TyCoVarSet Source #
expandTypeSynonyms :: Type -> Type Source #
Expand out all type synonyms. Actually, it'd suffice to expand out just the ones that discard type variables (e.g. type Funny a = Int) But we don't know which those are currently, so we just expand all.
expandTypeSynonyms
only expands out type synonyms mentioned in the type,
not in the kinds of any TyCon or TyVar mentioned in the type.
Keep this synchronized with synonymTyConsOfType
Well-scoped lists of variables
dVarSetElemsWellScoped :: DVarSet -> [Var] Source #
Extract a well-scoped list of variables from a deterministic set of variables. The result is deterministic. NB: There used to exist varSetElemsWellScoped :: VarSet -> [Var] which took a non-deterministic set and produced a non-deterministic well-scoped list. If you care about the list being well-scoped you also most likely care about it being in deterministic order.
toposortTyVars :: [TyCoVar] -> [TyCoVar] Source #
Do a topological sort on a list of tyvars, so that binders occur before occurrences E.g. given [ a::k, k::*, b::k ] it'll return a well-scoped list [ k::*, a::k, b::k ]
This is a deterministic sorting operation (that is, doesn't depend on Uniques).
tyCoVarsOfTypeWellScoped :: Type -> [TyVar] Source #
Get the free vars of a type in scoped order
tyCoVarsOfTypesWellScoped :: [Type] -> [TyVar] Source #
Get the free vars of types in scoped order
Type comparison
eqType :: Type -> Type -> Bool Source #
Type equality on source types. Does not look through newtypes
or
PredType
s, but it does look through type synonyms.
This first checks that the kinds of the types are equal and then
checks whether the types are equal, ignoring casts and coercions.
(The kind check is a recursive call, but since all kinds have type
Type
, there is no need to check the types of kinds.)
See also Note [Non-trivial definitional equality] in TyCoRep.
eqTypeX :: RnEnv2 -> Type -> Type -> Bool Source #
Compare types with respect to a (presumably) non-empty RnEnv2
.
eqTypes :: [Type] -> [Type] -> Bool Source #
Type equality on lists of types, looking through type synonyms but not newtypes.
Forcing evaluation of types
Other views onto Types
coreView :: Type -> Maybe Type Source #
This function Strips off the top layer only of a type synonym
application (if any) its underlying representation type.
Returns Nothing if there is nothing to look through.
This function considers Constraint
to be a synonym of TYPE LiftedRep
.
By being non-recursive and inlined, this case analysis gets efficiently joined onto the case analysis that the caller is already doing
tcView :: Type -> Maybe Type Source #
Gives the typechecker view of a type. This unwraps synonyms but
leaves Constraint
alone. c.f. coreView, which turns Constraint into
TYPE LiftedRep. Returns Nothing if no unwrapping happens.
See also Note [coreView vs tcView]
tyConsOfType :: Type -> UniqSet TyCon Source #
All type constructors occurring in the type; looking through type synonyms, but not newtypes. When it finds a Class, it returns the class TyCon.
Main type substitution data types
Type & coercion substitution
The following invariants must hold of a TCvSubst
:
- The in-scope set is needed only to guide the generation of fresh uniques
- In particular, the kind of the type variables in the in-scope set is not relevant
- The substitution is only applied ONCE! This is because in general such application will not reach a fixed point.
Manipulating type substitutions
mkEmptyTCvSubst :: InScopeSet -> TCvSubst Source #
mkTCvSubst :: InScopeSet -> (TvSubstEnv, CvSubstEnv) -> TCvSubst Source #
zipTvSubst :: [TyVar] -> [Type] -> TCvSubst Source #
Generates the in-scope set for the TCvSubst
from the types in the incoming
environment. No CoVars, please!
mkTvSubstPrs :: [(TyVar, Type)] -> TCvSubst Source #
Generates the in-scope set for the TCvSubst
from the types in the
incoming environment. No CoVars, please!
getTvSubstEnv :: TCvSubst -> TvSubstEnv Source #
setTvSubstEnv :: TCvSubst -> TvSubstEnv -> TCvSubst Source #
zapTCvSubst :: TCvSubst -> TCvSubst Source #
getTCvInScope :: TCvSubst -> InScopeSet Source #
getTCvSubstRangeFVs :: TCvSubst -> VarSet Source #
Returns the free variables of the types in the range of a substitution as a non-deterministic set.
composeTCvSubstEnv :: InScopeSet -> (TvSubstEnv, CvSubstEnv) -> (TvSubstEnv, CvSubstEnv) -> (TvSubstEnv, CvSubstEnv) Source #
(compose env1 env2)(x)
is env1(env2(x))
; i.e. apply env2
then env1
.
It assumes that both are idempotent.
Typically, env1
is the refinement to a base substitution env2
composeTCvSubst :: TCvSubst -> TCvSubst -> TCvSubst Source #
Composes two substitutions, applying the second one provided first, like in function composition.
isEmptyTCvSubst :: TCvSubst -> Bool Source #
Performing substitution on types and kinds
substTy :: HasCallStack => TCvSubst -> Type -> Type Source #
Substitute within a Type
The substitution has to satisfy the invariants described in
Note [The substitution invariant].
substTys :: HasCallStack => TCvSubst -> [Type] -> [Type] Source #
Substitute within several Type
s
The substitution has to satisfy the invariants described in
Note [The substitution invariant].
substTyWith :: HasCallStack => [TyVar] -> [Type] -> Type -> Type Source #
Type substitution, see zipTvSubst
substTysWith :: [TyVar] -> [Type] -> [Type] -> [Type] Source #
Type substitution, see zipTvSubst
substTheta :: HasCallStack => TCvSubst -> ThetaType -> ThetaType Source #
Substitute within a ThetaType
The substitution has to satisfy the invariants described in
Note [The substitution invariant].
substTyAddInScope :: TCvSubst -> Type -> Type Source #
Substitute within a Type
after adding the free variables of the type
to the in-scope set. This is useful for the case when the free variables
aren't already in the in-scope set or easily available.
See also Note [The substitution invariant].
substTyUnchecked :: TCvSubst -> Type -> Type Source #
Substitute within a Type
disabling the sanity checks.
The problems that the sanity checks in substTy catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substTyUnchecked to
substTy and remove this function. Please don't use in new code.
substTysUnchecked :: TCvSubst -> [Type] -> [Type] Source #
Substitute within several Type
s disabling the sanity checks.
The problems that the sanity checks in substTys catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substTysUnchecked to
substTys and remove this function. Please don't use in new code.
substThetaUnchecked :: TCvSubst -> ThetaType -> ThetaType Source #
Substitute within a ThetaType
disabling the sanity checks.
The problems that the sanity checks in substTys catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substThetaUnchecked to
substTheta and remove this function. Please don't use in new code.
substTyWithUnchecked :: [TyVar] -> [Type] -> Type -> Type Source #
Type substitution, see zipTvSubst
. Disables sanity checks.
The problems that the sanity checks in substTy catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substTyUnchecked to
substTy and remove this function. Please don't use in new code.
substCoUnchecked :: TCvSubst -> Coercion -> Coercion Source #
Substitute within a Coercion
disabling sanity checks.
The problems that the sanity checks in substCo catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substCoUnchecked to
substCo and remove this function. Please don't use in new code.
substCoWithUnchecked :: [TyVar] -> [Type] -> Coercion -> Coercion Source #
Coercion substitution, see zipTvSubst
. Disables sanity checks.
The problems that the sanity checks in substCo catch are described in
Note [The substitution invariant].
The goal of #11371 is to migrate all the calls of substCoUnchecked to
substCo and remove this function. Please don't use in new code.
substTyVarBndr :: HasCallStack => TCvSubst -> TyVar -> (TCvSubst, TyVar) Source #
substTyVarBndrs :: HasCallStack => TCvSubst -> [TyVar] -> (TCvSubst, [TyVar]) Source #
cloneTyVarBndrs :: TCvSubst -> [TyVar] -> UniqSupply -> (TCvSubst, [TyVar]) Source #
Pretty-printing
pprParendType :: Type -> SDoc Source #
pprTyThingCategory :: TyThing -> SDoc Source #
pprShortTyThing :: TyThing -> SDoc Source #
pprTvBndr :: TyVarBinder -> SDoc Source #
pprTvBndrs :: [TyVarBinder] -> SDoc Source #
pprForAll :: [TyVarBinder] -> SDoc Source #
pprUserForAll :: [TyVarBinder] -> SDoc Source #
Print a user-level forall; see Note [When to print foralls]
pprSigmaType :: Type -> SDoc Source #
pprThetaArrowTy :: ThetaType -> SDoc Source #
pprParendKind :: Kind -> SDoc Source #
pprSourceTyCon :: TyCon -> SDoc Source #
A general-purpose pretty-printing precedence type.
pprWithTYPE :: Type -> SDoc Source #
This variant preserves any use of TYPE in a type, effectively locally setting -fprint-explicit-runtime-reps.
Tidying type related things up for printing
tidyOpenTypes :: TidyEnv -> [Type] -> (TidyEnv, [Type]) Source #
Grabs the free type variables, tidies them
and then uses tidyType
to work over the type itself
tidyTyCoVarBndrs :: TidyEnv -> [TyCoVar] -> (TidyEnv, [TyCoVar]) Source #
This tidies up a type for printing in an error message, or in an interface file.
It doesn't change the uniques at all, just the print names.
tidyFreeTyCoVars :: TidyEnv -> [TyCoVar] -> TidyEnv Source #
Add the free TyVar
s to the env in tidy form,
so that we can tidy the type they are free in
tidyOpenTyCoVar :: TidyEnv -> TyCoVar -> (TidyEnv, TyCoVar) Source #
Treat a new TyCoVar
as a binder, and give it a fresh tidy name
using the environment if one has not already been allocated. See
also tidyTyCoVarBndr